18983640 has 128 divisors (see below), whose sum is σ = 62979840. Its totient is φ = 4548096.

The previous prime is 18983639. The next prime is 18983659. The reversal of 18983640 is 4638981.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 66939 + ... + 67221.

It is an arithmetic number, because the mean of its divisors is an integer number (492030).

Almost surely, 2^18983640 is an apocalyptic number.

18983640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18983640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31489920).

18983640 is an abundant number, since it is smaller than the sum of its proper divisors (43996200).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18983640 is a wasteful number, since it uses less digits than its factorization.

18983640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 353 (or 349 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 39.

The square root of 18983640 is about 4357.0219186963. The cubic root of 18983640 is about 266.7635550709.

The spelling of 18983640 in words is "eighteen million, nine hundred eighty-three thousand, six hundred forty".